Histology: Embedding Process

Summary

This video script provides a step-by-step guide for embedding tissue samples in paraffin, detailing the necessary equipment and procedures. It covers the use of various size molds, forceps, cassettes, and paraffin gloves, ensuring proper temperature and paraffin levels. The process involves carefully orienting tissue within molds, adding paraffin to anchor the tissue, and solidifying the block on a cold plate for sectioning. Emphasis is placed on maintaining specimen integrity and handling paraffin to prevent crystal formation. The final step involves cleaning the paraffin block and organizing it for storage.

Takeaways

• 😀 Ensure you have the necessary equipment: paraffin gloves, various size molds, forceps, cassettes, and sometimes plastic and metal molds.
• 😀 Turn on the cold plate to the embedding center and check that the paraffin temperature is set correctly (61°C).
• 😀 Make sure the paraffin chamber is full and ready for use.
• 😀 Place empty cassettes in the paraffin reservoir in numerical order before beginning the process.
• 😀 Open one cassette at a time carefully to maintain specimen integrity.
• 😀 Choose the appropriate size mold, considering size restrictions of the tissue sample.
• 😀 Place a small amount of paraffin in the mold, and orient the tissue correctly, ensuring it's positioned parallel to the bottom of the mold.
• 😀 Tissue may need to be positioned on edge, on end, or with the epithelium facing the same direction across all samples.
• 😀 Allow the hot paraffin to cool just enough to anchor the tissue in place without solidifying completely.
• 😀 Place the cassette top over the mold and fill it completely with paraffin, ensuring thorough coverage of the tissue.
• 😀 Set the combined mold and cassette onto the cold plate for rapid solidification to prevent large wax crystals from forming.
• 😀 Once the paraffin block has solidified, remove it from the mold and clean off any excess paraffin without compromising patient information.
• 😀 Organize the solidified blocks in an orderly fashion in a box for further processing.

Q & A

What equipment is needed for this practice?

You will need paraffin gloves, various size molds, forceps, cassettes, and both plastic and metal molds for this procedure.

What is the correct temperature setting for the paraffin?

The paraffin should be set to 61°C for optimal results.

How should the paraffin chamber be prepared?

Ensure that the paraffin chamber is full of paraffin before starting the procedure.

How should cassettes be placed in the paraffin reservoir?

Place the empty cassettes in the paraffin reservoir in numerical order.

What is the correct technique for opening the cassette?

Open one cassette at a time carefully, ensuring that the specimen integrity is maintained.

How do you choose the appropriate size mold for the tissue?

Select a mold size based on the size restrictions of the tissue sample.

How should the tissue be oriented in the mold?

The tissue should be oriented correctly in the mold, ensuring it is positioned parallel to the bottom, either on edge, end, or with the epithelium facing the correct direction.

How long should the paraffin be allowed to cool?

Allow the paraffin to cool only long enough to anchor the tissue in place before proceeding.

What is the purpose of placing the combined mold and cassette onto the cold plate?

Placing the mold and cassette onto the cold plate allows for rapid solidification of the paraffin block, which is necessary for proper sectioning.

What is the importance of rapid paraffin solidification?

Rapid solidification prevents the formation of large crystals in the wax, which can compromise the quality of the paraffin block.